Fix a failing test

Let consumers know that we have type annotations

.travis.yml

@@ -7,9 +7,12 @@ python:
   - 3.6
   - 3.7
   - 3.8.2
+  - nightly
   - pypy2.7-6.0
   - pypy3.5-6.0
 matrix:
+  allow_failures:
+    - python: nightly
   include:
     - python: 3.5
       env: TOXENV=py35-coverage

AUTHORS.txt

@@ -50,6 +50,8 @@ Daniel Fiterman (@dfit99) <fitermandaniel2@gmail.com>
 Simon Ruggier (@sruggier)
 Élie Gouzien (@ElieGouzien)
 Tim Gates (@timgates42) <tim.gates@iress.com>
+Batuhan Taskaya (@isidentical) <isidentical@gmail.com>
+Jocelyn Boullier (@Kazy) <jocelyn@boullier.bzh>
 
 
 Note: (@user) means a github user name.

CHANGELOG.rst

@@ -3,6 +3,14 @@
 Changelog
 ---------
 
+0.7.1 (2020-07-24)
+++++++++++++++++++
+
+- Fixed a couple of smaller bugs (mostly syntax error detection in
+  ``Grammar.iter_errors``)
+
+This is going to be the last release that supports Python 2.7, 3.4 and 3.5.
+
 0.7.0 (2020-04-13)
 ++++++++++++++++++
 

README.rst

@@ -11,6 +11,10 @@ parso - A Python Parser
     :target: https://coveralls.io/github/davidhalter/parso?branch=master
     :alt: Coverage Status
 
+.. image:: https://pepy.tech/badge/parso
+    :target: https://pepy.tech/project/parso
+    :alt: PyPI Downloads
+
 .. image:: https://raw.githubusercontent.com/davidhalter/parso/master/docs/_static/logo_characters.png
 
 Parso is a Python parser that supports error recovery and round-trip parsing

conftest.py

@@ -158,8 +158,17 @@ def works_ge_py35(each_version):
     version_info = parse_version_string(each_version)
     return Checker(each_version, version_info >= (3, 5))
 
+@pytest.fixture
+def works_ge_py36(each_version):
+    version_info = parse_version_string(each_version)
+    return Checker(each_version, version_info >= (3, 6))
 
 @pytest.fixture
 def works_ge_py38(each_version):
     version_info = parse_version_string(each_version)
     return Checker(each_version, version_info >= (3, 8))
+
+@pytest.fixture
+def works_ge_py39(each_version):
+    version_info = parse_version_string(each_version)
+    return Checker(each_version, version_info >= (3, 9))

deploy-master.sh

@@ -26,7 +26,7 @@ git checkout $BRANCH
 tox
 
 # Create tag
-tag=v$(python -c "import $PROJECT_NAME; print($PROJECT_NAME.__version__)")
+tag=v$(python3 -c "import $PROJECT_NAME; print($PROJECT_NAME.__version__)")
 
 master_ref=$(git show-ref -s heads/$BRANCH)
 tag_ref=$(git show-ref -s $tag || true)
@@ -43,7 +43,7 @@ fi
 # Package and upload to PyPI
 #rm -rf dist/ - Not needed anymore, because the folder is never reused.
 echo `pwd`
-python setup.py sdist bdist_wheel
+python3 setup.py sdist bdist_wheel
 # Maybe do a pip install twine before.
 twine upload dist/*
 

parso/__init__.py

@@ -43,7 +43,7 @@ from parso.grammar import Grammar, load_grammar
 from parso.utils import split_lines, python_bytes_to_unicode
 
 
-__version__ = '0.7.0'
+__version__ = '0.7.1'
 
 
 def parse(code=None, **kwargs):

parso/_compatibility.py

@@ -2,6 +2,7 @@
 To ensure compatibility from Python ``2.7`` - ``3.3``, a module has been
 created. Clearly there is huge need to use conforming syntax.
 """
+import os
 import sys
 import platform
 
@@ -44,11 +45,17 @@ def u(string):
 
 
 try:
-    # Python 2.7
+    # Python 3.3+
     FileNotFoundError = FileNotFoundError
 except NameError:
+    # Python 2.7 (both IOError + OSError)
+    FileNotFoundError = EnvironmentError
+try:
     # Python 3.3+
-    FileNotFoundError = IOError
+    PermissionError = PermissionError
+except NameError:
+    # Python 2.7 (both IOError + OSError)
+    PermissionError = EnvironmentError
 
 
 def utf8_repr(func):
@@ -67,3 +74,28 @@ def utf8_repr(func):
         return func
     else:
         return wrapper
+
+
+if sys.version_info < (3, 5):
+    """
+    A super-minimal shim around listdir that behave like
+    scandir for the information we need.
+    """
+    class _DirEntry:
+
+        def __init__(self, name, basepath):
+            self.name = name
+            self.basepath = basepath
+
+        @property
+        def path(self):
+            return os.path.join(self.basepath, self.name)
+
+        def stat(self):
+            # won't follow symlinks
+            return os.lstat(os.path.join(self.basepath, self.name))
+
+    def scandir(dir):
+        return [_DirEntry(name, dir) for name in os.listdir(dir)]
+else:
+    from os import scandir

parso/cache.py

@@ -7,13 +7,15 @@ import shutil
 import platform
 import errno
 import logging
+import warnings
 
 try:
     import cPickle as pickle
 except:
     import pickle
 
-from parso._compatibility import FileNotFoundError
+from parso._compatibility import FileNotFoundError, PermissionError, scandir
+from parso.file_io import FileIO
 
 LOG = logging.getLogger(__name__)
 
@@ -21,6 +23,13 @@ _CACHED_FILE_MINIMUM_SURVIVAL = 60 * 10  # 10 minutes
 """
 Cached files should survive at least a few minutes.
 """
+
+_CACHED_FILE_MAXIMUM_SURVIVAL = 60 * 60 * 24 * 30
+"""
+Maximum time for a cached file to survive if it is not
+accessed within.
+"""
+
 _CACHED_SIZE_TRIGGER = 600
 """
 This setting limits the amount of cached files. It's basically a way to start
@@ -63,7 +72,8 @@ http://docs.python.org/3/library/sys.html#sys.implementation
 
 def _get_default_cache_path():
     if platform.system().lower() == 'windows':
-        dir_ = os.path.join(os.getenv('LOCALAPPDATA') or '~', 'Parso', 'Parso')
+        dir_ = os.path.join(os.getenv('LOCALAPPDATA')
+                            or os.path.expanduser('~'), 'Parso', 'Parso')
     elif platform.system().lower() == 'darwin':
         dir_ = os.path.join('~', 'Library', 'Caches', 'Parso')
     else:
@@ -81,6 +91,19 @@ On Linux, if environment variable ``$XDG_CACHE_HOME`` is set,
 ``$XDG_CACHE_HOME/parso`` is used instead of the default one.
 """
 
+_CACHE_CLEAR_THRESHOLD = 60 * 60 * 24
+
+def _get_cache_clear_lock(cache_path = None):
+    """
+    The path where the cache lock is stored.
+
+    Cache lock will prevent continous cache clearing and only allow garbage
+    collection once a day (can be configured in _CACHE_CLEAR_THRESHOLD).
+    """
+    cache_path = cache_path or _get_default_cache_path()
+    return FileIO(os.path.join(cache_path, "PARSO-CACHE-LOCK"))
+
+
 parser_cache = {}
 
 
@@ -160,7 +183,7 @@ def _set_cache_item(hashed_grammar, path, module_cache_item):
     parser_cache.setdefault(hashed_grammar, {})[path] = module_cache_item
 
 
-def save_module(hashed_grammar, file_io, module, lines, pickling=True, cache_path=None):
+def try_to_save_module(hashed_grammar, file_io, module, lines, pickling=True, cache_path=None):
     path = file_io.path
     try:
         p_time = None if path is None else file_io.get_last_modified()
@@ -171,7 +194,18 @@ def save_module(hashed_grammar, file_io, module, lines, pickling=True, cache_pat
     item = _NodeCacheItem(module, lines, p_time)
     _set_cache_item(hashed_grammar, path, item)
     if pickling and path is not None:
+        try:
             _save_to_file_system(hashed_grammar, path, item, cache_path=cache_path)
+        except PermissionError:
+            # It's not really a big issue if the cache cannot be saved to the
+            # file system. It's still in RAM in that case. However we should
+            # still warn the user that this is happening.
+            warnings.warn(
+                'Tried to save a file to %s, but got permission denied.',
+                Warning
+            )
+        else:
+            _remove_cache_and_update_lock(cache_path=cache_path)
 
 
 def _save_to_file_system(hashed_grammar, path, item, cache_path=None):
@@ -186,6 +220,46 @@ def clear_cache(cache_path=None):
     parser_cache.clear()
 
 
+def clear_inactive_cache(
+    cache_path=None,
+    inactivity_threshold=_CACHED_FILE_MAXIMUM_SURVIVAL,
+):
+    if cache_path is None:
+        cache_path = _get_default_cache_path()
+    if not os.path.exists(cache_path):
+        return False
+    for version_path in os.listdir(cache_path):
+        version_path = os.path.join(cache_path, version_path)
+        if not os.path.isdir(version_path):
+            continue
+        for file in scandir(version_path):
+            if (
+                file.stat().st_atime + _CACHED_FILE_MAXIMUM_SURVIVAL
+                <= time.time()
+            ):
+                try:
+                    os.remove(file.path)
+                except OSError: # silently ignore all failures
+                    continue
+    else:
+        return True
+
+
+def _remove_cache_and_update_lock(cache_path = None):
+    lock = _get_cache_clear_lock(cache_path=cache_path)
+    clear_lock_time = lock.get_last_modified()
+    if (
+        clear_lock_time is None # first time
+        or clear_lock_time + _CACHE_CLEAR_THRESHOLD <= time.time()
+    ):
+        if not lock._touch():
+            # First make sure that as few as possible other cleanup jobs also
+            # get started. There is still a race condition but it's probably
+            # not a big problem.
+            return False
+
+        clear_inactive_cache(cache_path = cache_path)
+
 def _get_hashed_path(hashed_grammar, path, cache_path=None):
     directory = _get_cache_directory_path(cache_path=cache_path)
 

parso/file_io.py

@@ -1,4 +1,5 @@
 import os
+from parso._compatibility import FileNotFoundError
 
 
 class FileIO(object):
@@ -22,6 +23,17 @@ class FileIO(object):
             # Might raise FileNotFoundError, OSError for Python 2
             return None
 
+    def _touch(self):
+        try:
+            os.utime(self.path, None)
+        except FileNotFoundError:
+            try:
+                file = open(self.path, 'a')
+                file.close()
+            except (OSError, IOError):  # TODO Maybe log this?
+                return False
+        return True
+
     def __repr__(self):
         return '%s(%s)' % (self.__class__.__name__, self.path)
 

parso/grammar.py

@@ -7,7 +7,7 @@ from parso.utils import split_lines, python_bytes_to_unicode, parse_version_stri
 from parso.python.diff import DiffParser
 from parso.python.tokenize import tokenize_lines, tokenize
 from parso.python.token import PythonTokenTypes
-from parso.cache import parser_cache, load_module, save_module
+from parso.cache import parser_cache, load_module, try_to_save_module
 from parso.parser import BaseParser
 from parso.python.parser import Parser as PythonParser
 from parso.python.errors import ErrorFinderConfig
@@ -132,7 +132,7 @@ class Grammar(object):
                     old_lines=old_lines,
                     new_lines=lines
                 )
-                save_module(self._hashed, file_io, new_node, lines,
+                try_to_save_module(self._hashed, file_io, new_node, lines,
                             # Never pickle in pypy, it's slow as hell.
                             pickling=cache and not is_pypy,
                             cache_path=cache_path)
@@ -148,7 +148,7 @@ class Grammar(object):
         root_node = p.parse(tokens=tokens)
 
         if cache or diff_cache:
-            save_module(self._hashed, file_io, root_node, lines,
+            try_to_save_module(self._hashed, file_io, root_node, lines,
                         # Never pickle in pypy, it's slow as hell.
                         pickling=cache and not is_pypy,
                         cache_path=cache_path)
@@ -252,7 +252,7 @@ def load_grammar(**kwargs):
                     grammar = PythonGrammar(version_info, bnf_text)
                     return _loaded_grammars.setdefault(path, grammar)
                 except FileNotFoundError:
-                    message = "Python version %s is currently not supported." % version
+                    message = "Python version %s.%s is currently not supported." % (version_info.major, version_info.minor)
                     raise NotImplementedError(message)
         else:
             raise NotImplementedError("No support for language %s." % language)

parso/normalizer.py

@@ -163,7 +163,7 @@ class Rule(object):
     def get_node(self, node):
         return node
 
-    def _get_message(self, message):
+    def _get_message(self, message, node):
         if message is None:
             message = self.message
             if message is None:
@@ -176,7 +176,7 @@ class Rule(object):
             if code is None:
                 raise ValueError("The error code on the class is not set.")
 
-        message = self._get_message(message)
+        message = self._get_message(message, node)
 
         self._normalizer.add_issue(node, code, message)
 

parso/pgen2/generator.py

@@ -212,7 +212,8 @@ def _dump_nfa(start, finish):
     todo = [start]
     for i, state in enumerate(todo):
         print("  State", i, state is finish and "(final)" or "")
-        for label, next_ in state.arcs:
+        for arc in state.arcs:
+            label, next_ = arc.nonterminal_or_string, arc.next
             if next_ in todo:
                 j = todo.index(next_)
             else:
@@ -244,7 +245,7 @@ def generate_grammar(bnf_grammar, token_namespace):
     rule_to_dfas = {}
     start_nonterminal = None
     for nfa_a, nfa_z in GrammarParser(bnf_grammar).parse():
-        #_dump_nfa(a, z)
+        #_dump_nfa(nfa_a, nfa_z)
         dfas = _make_dfas(nfa_a, nfa_z)
         #_dump_dfas(dfas)
         # oldlen = len(dfas)

parso/python/errors.py

@@ -6,6 +6,7 @@ from contextlib import contextmanager
 
 from parso.normalizer import Normalizer, NormalizerConfig, Issue, Rule
 from parso.python.tree import search_ancestor
+from parso.python.tokenize import _get_token_collection
 
 _BLOCK_STMTS = ('if_stmt', 'while_stmt', 'for_stmt', 'try_stmt', 'with_stmt')
 _STAR_EXPR_PARENTS = ('testlist_star_expr', 'testlist_comp', 'exprlist')
@@ -13,11 +14,84 @@ _STAR_EXPR_PARENTS = ('testlist_star_expr', 'testlist_comp', 'exprlist')
 _MAX_BLOCK_SIZE = 20
 _MAX_INDENT_COUNT = 100
 ALLOWED_FUTURES = (
-    'all_feature_names', 'nested_scopes', 'generators', 'division',
+    'nested_scopes', 'generators', 'division', 'absolute_import',
-    'absolute_import', 'with_statement', 'print_function', 'unicode_literals',
+    'with_statement', 'print_function', 'unicode_literals',
 )
 _COMP_FOR_TYPES = ('comp_for', 'sync_comp_for')
 
+def _get_rhs_name(node, version):
+    type_ = node.type
+    if type_ == "lambdef":
+        return "lambda"
+    elif type_ == "atom":
+        comprehension = _get_comprehension_type(node)
+        first, second = node.children[:2]
+        if comprehension is not None:
+            return comprehension
+        elif second.type == "dictorsetmaker":
+            if version < (3, 8):
+                return "literal"
+            else:
+                if second.children[1] == ":" or second.children[0] == "**":
+                    return "dict display"
+                else:
+                    return "set display"
+        elif (
+            first == "("
+            and (second == ")"
+            or (len(node.children) == 3 and node.children[1].type == "testlist_comp"))
+        ):
+            return "tuple"
+        elif first == "(":
+            return _get_rhs_name(_remove_parens(node), version=version)
+        elif first == "[":
+            return "list"
+        elif first == "{" and second == "}":
+            return "dict display"
+        elif first == "{" and len(node.children) > 2:
+            return "set display"
+    elif type_ == "keyword":
+        if "yield" in node.value:
+            return "yield expression"
+        if version < (3, 8):
+            return "keyword"
+        else:
+            return str(node.value)
+    elif type_ == "operator" and node.value == "...":
+        return "Ellipsis"
+    elif type_ == "comparison":
+        return "comparison"
+    elif type_ in ("string", "number", "strings"):
+        return "literal"
+    elif type_ == "yield_expr":
+        return "yield expression"
+    elif type_ == "test":
+        return "conditional expression"
+    elif type_ in ("atom_expr", "power"):
+        if node.children[0] == "await":
+            return "await expression"
+        elif node.children[-1].type == "trailer":
+            trailer = node.children[-1]
+            if trailer.children[0] == "(":
+                return "function call"
+            elif trailer.children[0] == "[":
+                return "subscript"
+            elif trailer.children[0] == ".":
+                return "attribute"
+    elif (
+        ("expr" in type_
+        and "star_expr" not in type_)  # is a substring
+        or "_test" in type_
+        or type_ in ("term", "factor")
+    ):
+        return "operator"
+    elif type_ == "star_expr":
+        return "starred"
+    elif type_ == "testlist_star_expr":
+        return "tuple"
+    elif type_ == "fstring":
+        return "f-string expression"
+    return type_ # shouldn't reach here
 
 def _iter_stmts(scope):
     """
@@ -136,6 +210,21 @@ def _get_for_stmt_definition_exprs(for_stmt):
     return list(_iter_definition_exprs_from_lists(exprlist))
 
 
+def _is_argument_comprehension(argument):
+    return argument.children[1].type in _COMP_FOR_TYPES
+
+
+def _any_fstring_error(version, node):
+    if version < (3, 9) or node is None:
+        return False
+    if node.type == "error_node":
+        return any(child.type == "fstring_start" for child in node.children)
+    elif node.type == "fstring":
+        return True
+    else:
+        return search_ancestor(node, "fstring")
+
+
 class _Context(object):
     def __init__(self, node, add_syntax_error, parent_context=None):
         self.node = node
@@ -333,6 +422,11 @@ class ErrorFinder(Normalizer):
                     match = re.match('\\w{,2}("{1,3}|\'{1,3})', leaf.value)
                     if match is None:
                         message = 'invalid syntax'
+                        if (
+                            self.version >= (3, 9)
+                            and leaf.value in _get_token_collection(self.version).always_break_tokens
+                        ):
+                            message = "f-string: " + message
                     else:
                         if len(match.group(1)) == 1:
                             message = 'EOL while scanning string literal'
@@ -371,8 +465,8 @@ class ErrorFinder(Normalizer):
 class IndentationRule(Rule):
     code = 903
 
-    def _get_message(self, message):
+    def _get_message(self, message, node):
-        message = super(IndentationRule, self)._get_message(message)
+        message = super(IndentationRule, self)._get_message(message, node)
         return "IndentationError: " + message
 
 
@@ -396,21 +490,34 @@ class ErrorFinderConfig(NormalizerConfig):
 class SyntaxRule(Rule):
     code = 901
 
-    def _get_message(self, message):
+    def _get_message(self, message, node):
-        message = super(SyntaxRule, self)._get_message(message)
+        message = super(SyntaxRule, self)._get_message(message, node)
+        if (
+            "f-string" not in message
+            and _any_fstring_error(self._normalizer.version, node)
+        ):
+            message = "f-string: " + message
         return "SyntaxError: " + message
 
 
 @ErrorFinder.register_rule(type='error_node')
 class _InvalidSyntaxRule(SyntaxRule):
     message = "invalid syntax"
+    fstring_message = "f-string: invalid syntax"
 
     def get_node(self, node):
         return node.get_next_leaf()
 
     def is_issue(self, node):
+        error = node.get_next_leaf().type != 'error_leaf'
+        if (
+            error
+            and _any_fstring_error(self._normalizer.version, node)
+        ):
+            self.add_issue(node, message=self.fstring_message)
+        else:
             # Error leafs will be added later as an error.
-        return node.get_next_leaf().type != 'error_leaf'
+            return error
 
 
 @ErrorFinder.register_rule(value='await')
@@ -449,7 +556,11 @@ class _ContinueChecks(SyntaxRule):
                 in_loop = True
             if block.type == 'try_stmt':
                 last_block = block.children[-3]
-                if last_block == 'finally' and leaf.start_pos > last_block.start_pos:
+                if (
+                    last_block == "finally"
+                    and leaf.start_pos > last_block.start_pos
+                    and self._normalizer.version < (3, 8)
+                ):
                     self.add_issue(leaf, message=self.message_in_finally)
                     return False  # Error already added
         if not in_loop:
@@ -622,26 +733,24 @@ class _FutureImportRule(SyntaxRule):
                 allowed_futures = list(ALLOWED_FUTURES)
                 if self._normalizer.version >= (3, 5):
                     allowed_futures.append('generator_stop')
-
+                if self._normalizer.version >= (3, 7):
+                    allowed_futures.append('annotations')
                 if name == 'braces':
                     self.add_issue(node, message="not a chance")
                 elif name == 'barry_as_FLUFL':
                     m = "Seriously I'm not implementing this :) ~ Dave"
                     self.add_issue(node, message=m)
-                elif name not in ALLOWED_FUTURES:
+                elif name not in allowed_futures:
                     message = "future feature %s is not defined" % name
                     self.add_issue(node, message=message)
 
 
 @ErrorFinder.register_rule(type='star_expr')
 class _StarExprRule(SyntaxRule):
-    message = "starred assignment target must be in a list or tuple"
     message_iterable_unpacking = "iterable unpacking cannot be used in comprehension"
     message_assignment = "can use starred expression only as assignment target"
 
     def is_issue(self, node):
-        if node.parent.type not in _STAR_EXPR_PARENTS:
-            return True
         if node.parent.type == 'testlist_comp':
             # [*[] for a in [1]]
             if node.parent.children[1].type in _COMP_FOR_TYPES:
@@ -665,6 +774,9 @@ class _StarExprRule(SyntaxRule):
 class _StarExprParentRule(SyntaxRule):
     def is_issue(self, node):
         if node.parent.type == 'del_stmt':
+            if self._normalizer.version >= (3, 9):
+                self.add_issue(node.parent, message="cannot delete starred")
+            else:
                 self.add_issue(node.parent, message="can't use starred expression here")
         else:
             def is_definition(node, ancestor):
@@ -684,7 +796,10 @@ class _StarExprParentRule(SyntaxRule):
                 args = [c for c in node.children if c != ',']
                 starred = [c for c in args if c.type == 'star_expr']
                 if len(starred) > 1:
+                    if self._normalizer.version < (3, 9):
                         message = "two starred expressions in assignment"
+                    else:
+                        message = "multiple starred expressions in assignment"
                     self.add_issue(starred[1], message=message)
                 elif starred:
                     count = args.index(starred[0])
@@ -734,6 +849,9 @@ class _AnnotatorRule(SyntaxRule):
 class _ArgumentRule(SyntaxRule):
     def is_issue(self, node):
         first = node.children[0]
+        if self._normalizer.version < (3, 8):
+            # a((b)=c) is valid in <3.8
+            first = _remove_parens(first)
         if node.children[1] == '=' and first.type != 'name':
             if first.type == 'lambdef':
                 # f(lambda: 1=1)
@@ -749,6 +867,9 @@ class _ArgumentRule(SyntaxRule):
                     message = 'expression cannot contain assignment, perhaps you meant "=="?'
             self.add_issue(first, message=message)
 
+        if _is_argument_comprehension(node) and node.parent.type == 'classdef':
+            self.add_issue(node, message='invalid syntax')
+
 
 @ErrorFinder.register_rule(type='nonlocal_stmt')
 class _NonlocalModuleLevelRule(SyntaxRule):
@@ -768,12 +889,6 @@ class _ArglistRule(SyntaxRule):
             return "Generator expression must be parenthesized"
 
     def is_issue(self, node):
-        first_arg = node.children[0]
-        if first_arg.type == 'argument' \
-                and first_arg.children[1].type in _COMP_FOR_TYPES:
-            # e.g. foo(x for x in [], b)
-            return len(node.children) >= 2
-        else:
         arg_set = set()
         kw_only = False
         kw_unpacking_only = False
@@ -795,6 +910,10 @@ class _ArglistRule(SyntaxRule):
 
             if argument.type == 'argument':
                 first = argument.children[0]
+                if _is_argument_comprehension(argument) and len(node.children) >= 2:
+                    # a(a, b for b in c)
+                    return True
+
                 if first in ('*', '**'):
                     if first == '*':
                         if kw_unpacking_only:
@@ -809,7 +928,10 @@ class _ArglistRule(SyntaxRule):
                     if first.type == 'name':
                         if first.value in arg_set:
                             # f(x=1, x=2)
-                                self.add_issue(first, message="keyword argument repeated")
+                            message = "keyword argument repeated"
+                            if self._normalizer.version >= (3, 9):
+                                message += ": {}".format(first.value)
+                            self.add_issue(first, message=message)
                         else:
                             arg_set.add(first.value)
             else:
@@ -898,7 +1020,7 @@ class _FStringRule(SyntaxRule):
 
 
 class _CheckAssignmentRule(SyntaxRule):
-    def _check_assignment(self, node, is_deletion=False, is_namedexpr=False):
+    def _check_assignment(self, node, is_deletion=False, is_namedexpr=False, is_aug_assign=False):
         error = None
         type_ = node.type
         if type_ == 'lambdef':
@@ -915,6 +1037,16 @@ class _CheckAssignmentRule(SyntaxRule):
                             error = 'dict display'
                         else:
                             error = 'set display'
+                elif first == "{" and second == "}":
+                    if self._normalizer.version < (3, 8):
+                        error = 'literal'
+                    else:
+                        error = "dict display"
+                elif first == "{" and len(node.children) > 2:
+                    if self._normalizer.version < (3, 8):
+                        error = 'literal'
+                    else:
+                        error = "set display"
                 elif first in ('(', '['):
                     if second.type == 'yield_expr':
                         error = 'yield expression'
@@ -930,11 +1062,13 @@ class _CheckAssignmentRule(SyntaxRule):
                         # This is not a comprehension, they were handled
                         # further above.
                         for child in second.children[::2]:
-                            self._check_assignment(child, is_deletion, is_namedexpr)
+                            self._check_assignment(child, is_deletion, is_namedexpr, is_aug_assign)
                     else:  # Everything handled, must be useless brackets.
-                        self._check_assignment(second, is_deletion, is_namedexpr)
+                        self._check_assignment(second, is_deletion, is_namedexpr, is_aug_assign)
         elif type_ == 'keyword':
-            if self._normalizer.version < (3, 8):
+            if node.value == "yield":
+                error = "yield expression"
+            elif self._normalizer.version < (3, 8):
                 error = 'keyword'
             else:
                 error = str(node.value)
@@ -966,13 +1100,28 @@ class _CheckAssignmentRule(SyntaxRule):
                     error = 'subscript'
                 elif is_namedexpr and trailer.children[0] == '.':
                     error = 'attribute'
+        elif type_ == "fstring":
+            if self._normalizer.version < (3, 8):
+                error = 'literal'
+            else:
+                error = "f-string expression"
         elif type_ in ('testlist_star_expr', 'exprlist', 'testlist'):
             for child in node.children[::2]:
-                self._check_assignment(child, is_deletion, is_namedexpr)
+                self._check_assignment(child, is_deletion, is_namedexpr, is_aug_assign)
         elif ('expr' in type_ and type_ != 'star_expr'  # is a substring
               or '_test' in type_
               or type_ in ('term', 'factor')):
             error = 'operator'
+        elif type_ == "star_expr":
+            if is_deletion:
+                if self._normalizer.version >= (3, 9):
+                    error = "starred"
+                else:
+                    self.add_issue(node, message="can't use starred expression here")
+            elif not search_ancestor(node, *_STAR_EXPR_PARENTS) and not is_aug_assign:
+                self.add_issue(node, message="starred assignment target must be in a list or tuple")
+
+            self._check_assignment(node.children[1])
 
         if error is not None:
             if is_namedexpr:
@@ -999,15 +1148,35 @@ class _CompForRule(_CheckAssignmentRule):
 @ErrorFinder.register_rule(type='expr_stmt')
 class _ExprStmtRule(_CheckAssignmentRule):
     message = "illegal expression for augmented assignment"
-
+    extended_message = "'{target}' is an " + message
     def is_issue(self, node):
-        for before_equal in node.children[:-2:2]:
-            self._check_assignment(before_equal)
-
         augassign = node.children[1]
-        if augassign != '=' and augassign.type != 'annassign':  # Is augassign.
+        is_aug_assign = augassign != '=' and augassign.type != 'annassign'
-            return node.children[0].type in ('testlist_star_expr', 'atom', 'testlist')
 
+        if self._normalizer.version <= (3, 8) or not is_aug_assign:
+            for before_equal in node.children[:-2:2]:
+                self._check_assignment(before_equal, is_aug_assign=is_aug_assign)
+
+        if is_aug_assign:
+            target = _remove_parens(node.children[0])
+            # a, a[b], a.b
+
+            if target.type == "name" or (
+                target.type in ("atom_expr", "power")
+                and target.children[1].type == "trailer"
+                and target.children[-1].children[0] != "("
+            ):
+                return False
+
+            if self._normalizer.version <= (3, 8):
+                return True
+            else:
+                self.add_issue(
+                    node,
+                    message=self.extended_message.format(
+                        target=_get_rhs_name(node.children[0], self._normalizer.version)
+                    ),
+                )
 
 @ErrorFinder.register_rule(type='with_item')
 class _WithItemRule(_CheckAssignmentRule):

parso/python/grammar310.txt

@@ -0,0 +1,171 @@
+# Grammar for Python
+
+# NOTE WELL: You should also follow all the steps listed at
+# https://devguide.python.org/grammar/
+
+# Start symbols for the grammar:
+#       single_input is a single interactive statement;
+#       file_input is a module or sequence of commands read from an input file;
+#       eval_input is the input for the eval() functions.
+# NB: compound_stmt in single_input is followed by extra NEWLINE!
+single_input: NEWLINE | simple_stmt | compound_stmt NEWLINE
+file_input: stmt* ENDMARKER
+eval_input: testlist NEWLINE* ENDMARKER
+
+decorator: '@' namedexpr_test NEWLINE
+decorators: decorator+
+decorated: decorators (classdef | funcdef | async_funcdef)
+
+async_funcdef: 'async' funcdef
+funcdef: 'def' NAME parameters ['->' test] ':' suite
+
+parameters: '(' [typedargslist] ')'
+typedargslist: (
+  (tfpdef ['=' test] (',' tfpdef ['=' test])* ',' '/' [',' [ tfpdef ['=' test] (
+        ',' tfpdef ['=' test])* ([',' [
+        '*' [tfpdef] (',' tfpdef ['=' test])* [',' ['**' tfpdef [',']]]
+      | '**' tfpdef [',']]])
+  | '*' [tfpdef] (',' tfpdef ['=' test])* ([',' ['**' tfpdef [',']]])
+  | '**' tfpdef [',']]] )
+|  (tfpdef ['=' test] (',' tfpdef ['=' test])* [',' [
+        '*' [tfpdef] (',' tfpdef ['=' test])* [',' ['**' tfpdef [',']]]
+      | '**' tfpdef [',']]]
+  | '*' [tfpdef] (',' tfpdef ['=' test])* [',' ['**' tfpdef [',']]]
+  | '**' tfpdef [','])
+)
+tfpdef: NAME [':' test]
+varargslist: vfpdef ['=' test ](',' vfpdef ['=' test])* ',' '/' [',' [ (vfpdef ['=' test] (',' vfpdef ['=' test])* [',' [
+        '*' [vfpdef] (',' vfpdef ['=' test])* [',' ['**' vfpdef [',']]]
+      | '**' vfpdef [',']]]
+  | '*' [vfpdef] (',' vfpdef ['=' test])* [',' ['**' vfpdef [',']]]
+  | '**' vfpdef [',']) ]] | (vfpdef ['=' test] (',' vfpdef ['=' test])* [',' [
+        '*' [vfpdef] (',' vfpdef ['=' test])* [',' ['**' vfpdef [',']]]
+      | '**' vfpdef [',']]]
+  | '*' [vfpdef] (',' vfpdef ['=' test])* [',' ['**' vfpdef [',']]]
+  | '**' vfpdef [',']
+)
+vfpdef: NAME
+
+stmt: simple_stmt | compound_stmt | NEWLINE
+simple_stmt: small_stmt (';' small_stmt)* [';'] NEWLINE
+small_stmt: (expr_stmt | del_stmt | pass_stmt | flow_stmt |
+             import_stmt | global_stmt | nonlocal_stmt | assert_stmt)
+expr_stmt: testlist_star_expr (annassign | augassign (yield_expr|testlist) |
+                     ('=' (yield_expr|testlist_star_expr))*)
+annassign: ':' test ['=' (yield_expr|testlist_star_expr)]
+testlist_star_expr: (test|star_expr) (',' (test|star_expr))* [',']
+augassign: ('+=' | '-=' | '*=' | '@=' | '/=' | '%=' | '&=' | '|=' | '^=' |
+            '<<=' | '>>=' | '**=' | '//=')
+# For normal and annotated assignments, additional restrictions enforced by the interpreter
+del_stmt: 'del' exprlist
+pass_stmt: 'pass'
+flow_stmt: break_stmt | continue_stmt | return_stmt | raise_stmt | yield_stmt
+break_stmt: 'break'
+continue_stmt: 'continue'
+return_stmt: 'return' [testlist_star_expr]
+yield_stmt: yield_expr
+raise_stmt: 'raise' [test ['from' test]]
+import_stmt: import_name | import_from
+import_name: 'import' dotted_as_names
+# note below: the ('.' | '...') is necessary because '...' is tokenized as ELLIPSIS
+import_from: ('from' (('.' | '...')* dotted_name | ('.' | '...')+)
+              'import' ('*' | '(' import_as_names ')' | import_as_names))
+import_as_name: NAME ['as' NAME]
+dotted_as_name: dotted_name ['as' NAME]
+import_as_names: import_as_name (',' import_as_name)* [',']
+dotted_as_names: dotted_as_name (',' dotted_as_name)*
+dotted_name: NAME ('.' NAME)*
+global_stmt: 'global' NAME (',' NAME)*
+nonlocal_stmt: 'nonlocal' NAME (',' NAME)*
+assert_stmt: 'assert' test [',' test]
+
+compound_stmt: if_stmt | while_stmt | for_stmt | try_stmt | with_stmt | funcdef | classdef | decorated | async_stmt
+async_stmt: 'async' (funcdef | with_stmt | for_stmt)
+if_stmt: 'if' namedexpr_test ':' suite ('elif' namedexpr_test ':' suite)* ['else' ':' suite]
+while_stmt: 'while' namedexpr_test ':' suite ['else' ':' suite]
+for_stmt: 'for' exprlist 'in' testlist ':' suite ['else' ':' suite]
+try_stmt: ('try' ':' suite
+           ((except_clause ':' suite)+
+            ['else' ':' suite]
+            ['finally' ':' suite] |
+           'finally' ':' suite))
+with_stmt: 'with' with_item (',' with_item)*  ':' suite
+with_item: test ['as' expr]
+# NB compile.c makes sure that the default except clause is last
+except_clause: 'except' [test ['as' NAME]]
+suite: simple_stmt | NEWLINE INDENT stmt+ DEDENT
+
+namedexpr_test: test [':=' test]
+test: or_test ['if' or_test 'else' test] | lambdef
+test_nocond: or_test | lambdef_nocond
+lambdef: 'lambda' [varargslist] ':' test
+lambdef_nocond: 'lambda' [varargslist] ':' test_nocond
+or_test: and_test ('or' and_test)*
+and_test: not_test ('and' not_test)*
+not_test: 'not' not_test | comparison
+comparison: expr (comp_op expr)*
+# <> isn't actually a valid comparison operator in Python. It's here for the
+# sake of a __future__ import described in PEP 401 (which really works :-)
+comp_op: '<'|'>'|'=='|'>='|'<='|'<>'|'!='|'in'|'not' 'in'|'is'|'is' 'not'
+star_expr: '*' expr
+expr: xor_expr ('|' xor_expr)*
+xor_expr: and_expr ('^' and_expr)*
+and_expr: shift_expr ('&' shift_expr)*
+shift_expr: arith_expr (('<<'|'>>') arith_expr)*
+arith_expr: term (('+'|'-') term)*
+term: factor (('*'|'@'|'/'|'%'|'//') factor)*
+factor: ('+'|'-'|'~') factor | power
+power: atom_expr ['**' factor]
+atom_expr: ['await'] atom trailer*
+atom: ('(' [yield_expr|testlist_comp] ')' |
+       '[' [testlist_comp] ']' |
+       '{' [dictorsetmaker] '}' |
+       NAME | NUMBER | strings | '...' | 'None' | 'True' | 'False')
+testlist_comp: (namedexpr_test|star_expr) ( comp_for | (',' (namedexpr_test|star_expr))* [','] )
+trailer: '(' [arglist] ')' | '[' subscriptlist ']' | '.' NAME
+subscriptlist: subscript (',' subscript)* [',']
+subscript: test | [test] ':' [test] [sliceop]
+sliceop: ':' [test]
+exprlist: (expr|star_expr) (',' (expr|star_expr))* [',']
+testlist: test (',' test)* [',']
+dictorsetmaker: ( ((test ':' test | '**' expr)
+                   (comp_for | (',' (test ':' test | '**' expr))* [','])) |
+                  ((test | star_expr)
+                   (comp_for | (',' (test | star_expr))* [','])) )
+
+classdef: 'class' NAME ['(' [arglist] ')'] ':' suite
+
+arglist: argument (',' argument)*  [',']
+
+# The reason that keywords are test nodes instead of NAME is that using NAME
+# results in an ambiguity. ast.c makes sure it's a NAME.
+# "test '=' test" is really "keyword '=' test", but we have no such token.
+# These need to be in a single rule to avoid grammar that is ambiguous
+# to our LL(1) parser. Even though 'test' includes '*expr' in star_expr,
+# we explicitly match '*' here, too, to give it proper precedence.
+# Illegal combinations and orderings are blocked in ast.c:
+# multiple (test comp_for) arguments are blocked; keyword unpackings
+# that precede iterable unpackings are blocked; etc.
+argument: ( test [comp_for] |
+            test ':=' test |
+            test '=' test |
+            '**' test |
+            '*' test )
+
+comp_iter: comp_for | comp_if
+sync_comp_for: 'for' exprlist 'in' or_test [comp_iter]
+comp_for: ['async'] sync_comp_for
+comp_if: 'if' test_nocond [comp_iter]
+
+# not used in grammar, but may appear in "node" passed from Parser to Compiler
+encoding_decl: NAME
+
+yield_expr: 'yield' [yield_arg]
+yield_arg: 'from' test | testlist_star_expr
+
+strings: (STRING | fstring)+
+fstring: FSTRING_START fstring_content* FSTRING_END
+fstring_content: FSTRING_STRING | fstring_expr
+fstring_conversion: '!' NAME
+fstring_expr: '{' testlist ['='] [ fstring_conversion ] [ fstring_format_spec ] '}'
+fstring_format_spec: ':' fstring_content*

parso/python/grammar38.txt

@@ -52,7 +52,7 @@ small_stmt: (expr_stmt | del_stmt | pass_stmt | flow_stmt |
              import_stmt | global_stmt | nonlocal_stmt | assert_stmt)
 expr_stmt: testlist_star_expr (annassign | augassign (yield_expr|testlist) |
                      ('=' (yield_expr|testlist_star_expr))*)
-annassign: ':' test ['=' test]
+annassign: ':' test ['=' (yield_expr|testlist_star_expr)]
 testlist_star_expr: (test|star_expr) (',' (test|star_expr))* [',']
 augassign: ('+=' | '-=' | '*=' | '@=' | '/=' | '%=' | '&=' | '|=' | '^=' |
             '<<=' | '>>=' | '**=' | '//=')

parso/python/grammar39.txt

@@ -12,7 +12,7 @@ single_input: NEWLINE | simple_stmt | compound_stmt NEWLINE
 file_input: stmt* ENDMARKER
 eval_input: testlist NEWLINE* ENDMARKER
 
-decorator: '@' dotted_name [ '(' [arglist] ')' ] NEWLINE
+decorator: '@' namedexpr_test NEWLINE
 decorators: decorator+
 decorated: decorators (classdef | funcdef | async_funcdef)
 
@@ -52,7 +52,7 @@ small_stmt: (expr_stmt | del_stmt | pass_stmt | flow_stmt |
              import_stmt | global_stmt | nonlocal_stmt | assert_stmt)
 expr_stmt: testlist_star_expr (annassign | augassign (yield_expr|testlist) |
                      ('=' (yield_expr|testlist_star_expr))*)
-annassign: ':' test ['=' test]
+annassign: ':' test ['=' (yield_expr|testlist_star_expr)]
 testlist_star_expr: (test|star_expr) (',' (test|star_expr))* [',']
 augassign: ('+=' | '-=' | '*=' | '@=' | '/=' | '%=' | '&=' | '|=' | '^=' |
             '<<=' | '>>=' | '**=' | '//=')

parso/python/tokenize.py

@@ -260,7 +260,7 @@ def _create_token_collection(version_info):
                            'finally', 'while', 'with', 'return', 'continue',
                            'break', 'del', 'pass', 'global', 'assert')
     if version_info >= (3, 5):
-        ALWAYS_BREAK_TOKENS += ('async', 'nonlocal')
+        ALWAYS_BREAK_TOKENS += ('nonlocal', )
     pseudo_token_compiled = _compile(PseudoToken)
     return TokenCollection(
         pseudo_token_compiled, single_quoted, triple_quoted, endpats,

parso/tree.py

@@ -168,7 +168,7 @@ class NodeOrLeaf(object):
     @abstractmethod
     def get_code(self, include_prefix=True):
         """
-        Returns the code that was input the input for the parser for this node.
+        Returns the code that was the input for the parser for this node.
 
         :param include_prefix: Removes the prefix (whitespace and comments) of
             e.g. a statement.

parso/utils.py

@@ -105,8 +105,17 @@ def python_bytes_to_unicode(source, encoding='utf-8', errors='strict'):
     if not isinstance(encoding, unicode):
         encoding = unicode(encoding, 'utf-8', 'replace')
 
+    try:
         # Cast to unicode
         return unicode(source, encoding, errors)
+    except LookupError:
+        if errors == 'replace':
+            # This is a weird case that can happen if the given encoding is not
+            # a valid encoding. This usually shouldn't happen with provided
+            # encodings, but can happen if somebody uses encoding declarations
+            # like `# coding: foo-8`.
+            return unicode(source, 'utf-8', errors)
+        raise
 
 
 def version_info():
@@ -120,7 +129,7 @@ def version_info():
 
 
 def _parse_version(version):
-    match = re.match(r'(\d+)(?:\.(\d)(?:\.\d+)?)?$', version)
+    match = re.match(r'(\d+)(?:\.(\d{1,2})(?:\.\d+)?)?((a|b|rc)\d)?$', version)
     if match is None:
         raise ValueError('The given version is not in the right format. '
                          'Use something like "3.8" or "3".')

setup.py

@@ -25,7 +25,7 @@ setup(name='parso',
       keywords='python parser parsing',
       long_description=readme,
       packages=find_packages(exclude=['test']),
-      package_data={'parso': ['python/grammar*.txt']},
+      package_data={'parso': ['python/grammar*.txt', 'py.typed', '*.pyi', '**/*.pyi']},
       platforms=['any'],
       python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*',
       classifiers=[
@@ -44,6 +44,7 @@ setup(name='parso',
           'Topic :: Software Development :: Libraries :: Python Modules',
           'Topic :: Text Editors :: Integrated Development Environments (IDE)',
           'Topic :: Utilities',
+          'Typing :: Typed',
       ],
       extras_require={
           'testing': [

test/failing_examples.py

@@ -52,9 +52,37 @@ FAILING_EXAMPLES = [
     'f(x=2, y)',
     'f(**x, *y)',
     'f(**x, y=3, z)',
+    # augassign
     'a, b += 3',
     '(a, b) += 3',
     '[a, b] += 3',
+    'f() += 1',
+    'lambda x:None+=1',
+    '{} += 1',
+    '{a:b} += 1',
+    '{1} += 1',
+    '{*x} += 1',
+    '(x,) += 1',
+    '(x, y if a else q) += 1',
+    '[] += 1',
+    '[1,2] += 1',
+    '[] += 1',
+    'None += 1',
+    '... += 1',
+    'a > 1 += 1',
+    '"test" += 1',
+    '1 += 1',
+    '1.0 += 1',
+    '(yield) += 1',
+    '(yield from x) += 1',
+    '(x if x else y) += 1',
+    'a() += 1',
+    'a + b += 1',
+    '+a += 1',
+    'a and b += 1',
+    '*a += 1',
+    'a, b += 1',
+    'f"xxx" += 1',
     # All assignment tests
     'lambda a: 1 = 1',
     '[x for x in y] = 1',
@@ -308,6 +336,12 @@ if sys.version_info[:2] <= (3, 4):
         '(*[1], 2)',
     ]
 
+if sys.version_info[:2] >= (3, 7):
+    # This is somehow ok in previous versions.
+    FAILING_EXAMPLES += [
+        'class X(base for base in bases): pass',
+    ]
+
 if sys.version_info[:2] < (3, 8):
     FAILING_EXAMPLES += [
         # Python/compile.c

test/normalizer_issue_files/allowed_syntax.py

@@ -12,13 +12,6 @@ from .__future__ import absolute_import
 ''r''u''
 b'' BR''
 
-for x in [1]:
-    try:
-        continue  # Only the other continue and pass is an error.
-    finally:
-        #: E901
-        continue
-
 
 for x in [1]:
     break

test/test_cache.py

@@ -2,28 +2,38 @@
 Test all things related to the ``jedi.cache`` module.
 """
 
-from os import unlink
+import os
+import os.path
 
 import pytest
 import time
 
-from parso.cache import _NodeCacheItem, save_module, load_module, \
+from parso.cache import (_CACHED_FILE_MAXIMUM_SURVIVAL, _VERSION_TAG,
-    _get_hashed_path, parser_cache, _load_from_file_system, _save_to_file_system
+                         _get_cache_clear_lock, _get_hashed_path,
+                         _load_from_file_system, _NodeCacheItem,
+                         _remove_cache_and_update_lock, _save_to_file_system,
+                         load_module, parser_cache, try_to_save_module)
+from parso._compatibility import is_pypy, PermissionError
 from parso import load_grammar
 from parso import cache
 from parso import file_io
 from parso import parse
 
+skip_pypy = pytest.mark.skipif(
+    is_pypy,
+    reason="pickling in pypy is slow, since we don't pickle,"
+           "we never go into path of auto-collecting garbage"
+)
+
 
 @pytest.fixture()
-def isolated_jedi_cache(monkeypatch, tmpdir):
+def isolated_parso_cache(monkeypatch, tmpdir):
-    """
+    """Set `parso.cache._default_cache_path` to a temporary directory
-    Set `jedi.settings.cache_directory` to a temporary directory during test.
+    during the test. """
-
+    cache_path = str(os.path.join(str(tmpdir), "__parso_cache"))
-    Same as `clean_jedi_cache`, but create the temporary directory for
+    monkeypatch.setattr(cache, '_default_cache_path', cache_path)
-    each test case (scope='function').
+    monkeypatch.setattr(cache, '_get_default_cache_path', lambda *args, **kwargs: cache_path)
-    """
+    return cache_path
-    monkeypatch.setattr(cache, '_default_cache_path', str(tmpdir))
 
 
 def test_modulepickling_change_cache_dir(tmpdir):
@@ -57,7 +67,7 @@ def load_stored_item(hashed_grammar, path, item, cache_path):
     return item
 
 
-@pytest.mark.usefixtures("isolated_jedi_cache")
+@pytest.mark.usefixtures("isolated_parso_cache")
 def test_modulepickling_simulate_deleted_cache(tmpdir):
     """
     Tests loading from a cache file after it is deleted.
@@ -81,10 +91,10 @@ def test_modulepickling_simulate_deleted_cache(tmpdir):
         pass
     io = file_io.FileIO(path)
 
-    save_module(grammar._hashed, io, module, lines=[])
+    try_to_save_module(grammar._hashed, io, module, lines=[])
     assert load_module(grammar._hashed, io) == module
 
-    unlink(_get_hashed_path(grammar._hashed, path))
+    os.unlink(_get_hashed_path(grammar._hashed, path))
     parser_cache.clear()
 
     cached2 = load_module(grammar._hashed, io)
@@ -139,3 +149,43 @@ def test_cache_last_used_update(diff_cache, use_file_io):
 
     node_cache_item = next(iter(parser_cache.values()))[p]
     assert now < node_cache_item.last_used < time.time()
+
+
+@skip_pypy
+def test_inactive_cache(tmpdir, isolated_parso_cache):
+    parser_cache.clear()
+    test_subjects = "abcdef"
+    for path in test_subjects:
+        parse('somecode', cache=True, path=os.path.join(str(tmpdir), path))
+    raw_cache_path = os.path.join(isolated_parso_cache, _VERSION_TAG)
+    assert os.path.exists(raw_cache_path)
+    paths = os.listdir(raw_cache_path)
+    a_while_ago = time.time() - _CACHED_FILE_MAXIMUM_SURVIVAL
+    old_paths = set()
+    for path in paths[:len(test_subjects) // 2]:  # make certain number of paths old
+        os.utime(os.path.join(raw_cache_path, path), (a_while_ago, a_while_ago))
+        old_paths.add(path)
+    # nothing should be cleared while the lock is on
+    assert os.path.exists(_get_cache_clear_lock().path)
+    _remove_cache_and_update_lock()  # it shouldn't clear anything
+    assert len(os.listdir(raw_cache_path)) == len(test_subjects)
+    assert old_paths.issubset(os.listdir(raw_cache_path))
+
+    os.utime(_get_cache_clear_lock().path, (a_while_ago, a_while_ago))
+    _remove_cache_and_update_lock()
+    assert len(os.listdir(raw_cache_path)) == len(test_subjects) // 2
+    assert not old_paths.intersection(os.listdir(raw_cache_path))
+
+
+@skip_pypy
+def test_permission_error(monkeypatch):
+    def save(*args, **kwargs):
+        was_called[0] = True  # Python 2... Use nonlocal instead
+        raise PermissionError
+
+    was_called = [False]
+
+    monkeypatch.setattr(cache, '_save_to_file_system', save)
+    with pytest.warns(Warning):
+        parse(path=__file__, cache=True, diff_cache=True)
+    assert was_called[0]

test/test_load_grammar.py

@@ -20,7 +20,7 @@ def test_parse_version(string, result):
     assert utils._parse_version(string) == result
 
 
-@pytest.mark.parametrize('string', ['1.', 'a', '#', '1.3.4.5', '1.12'])
+@pytest.mark.parametrize('string', ['1.', 'a', '#', '1.3.4.5'])
 def test_invalid_grammar_version(string):
     with pytest.raises(ValueError):
         load_grammar(version=string)

test/test_parser.py

@@ -194,6 +194,9 @@ def test_no_error_nodes(each_version):
 def test_named_expression(works_ge_py38):
     works_ge_py38.parse("(a := 1, a + 1)")
 
+def test_extended_rhs_annassign(works_ge_py38):
+    works_ge_py38.parse("x: y = z,")
+    works_ge_py38.parse("x: Tuple[int, ...] = z, *q, w")
 
 @pytest.mark.parametrize(
     'param_code', [
@@ -208,3 +211,13 @@ def test_named_expression(works_ge_py38):
 )
 def test_positional_only_arguments(works_ge_py38, param_code):
     works_ge_py38.parse("def x(%s): pass" % param_code)
+
+@pytest.mark.parametrize(
+    'expression', [
+        'a + a',
+        'lambda x: x',
+        'a := lambda x: x'
+    ]
+)
+def test_decorator_expression(works_ge_py39, expression):
+    works_ge_py39.parse("@%s\ndef x(): pass" % expression)

test/test_pgen2.py

@@ -87,6 +87,39 @@ def test_async_for(works_ge_py35):
     works_ge_py35.parse("async def foo():\n async for a in b: pass")
 
 
+@pytest.mark.parametrize("body", [
+    """[1 async for a in b
+    ]""",
+    """[1 async
+    for a in b
+    ]""",
+    """[
+    1
+    async for a in b
+    ]""",
+    """[
+    1
+    async for a
+    in b
+    ]""",
+    """[
+    1
+    async
+    for
+    a
+    in
+    b
+    ]""",
+    """  [
+    1 async for a in b
+  ]""",
+])
+def test_async_for_comprehension_newline(works_ge_py36, body):
+    # Issue #139
+    works_ge_py36.parse("""async def foo():
+    {}""".format(body))
+
+
 def test_async_with(works_ge_py35):
     works_ge_py35.parse("async def foo():\n async with a: pass")
 

test/test_python_errors.py

@@ -7,6 +7,8 @@ import warnings
 import pytest
 
 import parso
+
+from textwrap import dedent
 from parso._compatibility import is_pypy
 from .failing_examples import FAILING_EXAMPLES, indent, build_nested
 
@@ -185,12 +187,13 @@ def test_statically_nested_blocks():
 
 
 def test_future_import_first():
-    def is_issue(code, *args):
+    def is_issue(code, *args, **kwargs):
         code = code % args
-        return bool(_get_error_list(code))
+        return bool(_get_error_list(code, **kwargs))
 
     i1 = 'from __future__ import division'
     i2 = 'from __future__ import absolute_import'
+    i3 = 'from __future__ import annotations'
     assert not is_issue(i1)
     assert not is_issue(i1 + ';' + i2)
     assert not is_issue(i1 + '\n' + i2)
@@ -201,6 +204,8 @@ def test_future_import_first():
     assert not is_issue('""\n%s;%s', i1, i2)
     assert not is_issue('"";%s;%s ', i1, i2)
     assert not is_issue('"";%s\n%s ', i1, i2)
+    assert not is_issue(i3, version="3.7")
+    assert is_issue(i3, version="3.6")
     assert is_issue('1;' + i1)
     assert is_issue('1\n' + i1)
     assert is_issue('"";1\n' + i1)
@@ -268,6 +273,9 @@ def test_too_many_levels_of_indentation():
     assert not _get_error_list(build_nested('pass', 49, base=base))
     assert _get_error_list(build_nested('pass', 50, base=base))
 
+def test_paren_kwarg():
+    assert _get_error_list("print((sep)=seperator)", version="3.8")
+    assert not _get_error_list("print((sep)=seperator)", version="3.7")
 
 @pytest.mark.parametrize(
     'code', [
@@ -321,3 +329,88 @@ def test_invalid_fstrings(code, message):
 def test_trailing_comma(code):
     errors = _get_error_list(code)
     assert not errors
+
+def test_continue_in_finally():
+    code = dedent('''\
+        for a in [1]:
+            try:
+                pass
+            finally:
+                continue
+        ''')
+    assert not _get_error_list(code, version="3.8")
+    assert _get_error_list(code, version="3.7")
+
+    
+@pytest.mark.parametrize(
+    'template', [
+        "a, b, {target}, c = d",
+        "a, b, *{target}, c = d",
+        "(a, *{target}), c = d",
+        "for x, {target} in y: pass",
+        "for x, q, {target} in y: pass",
+        "for x, q, *{target} in y: pass",
+        "for (x, *{target}), q in y: pass",
+    ]
+)
+@pytest.mark.parametrize(
+    'target', [
+        "True",
+        "False",
+        "None",
+        "__debug__"
+    ]
+)
+def test_forbidden_name(template, target):
+    assert _get_error_list(template.format(target=target), version="3")
+
+
+def test_repeated_kwarg():
+    # python 3.9+ shows which argument is repeated
+    assert (
+        _get_error_list("f(q=1, q=2)", version="3.8")[0].message
+        == "SyntaxError: keyword argument repeated"
+    )
+    assert (
+        _get_error_list("f(q=1, q=2)", version="3.9")[0].message
+        == "SyntaxError: keyword argument repeated: q"
+    )
+
+
+@pytest.mark.parametrize(
+    ('source', 'no_errors'), [
+        ('a(a for a in b,)', False),
+        ('a(a for a in b, a)', False),
+        ('a(a, a for a in b)', False),
+        ('a(a, b, a for a in b, c, d)', False),
+        ('a(a for a in b)', True),
+        ('a((a for a in b), c)', True),
+        ('a(c, (a for a in b))', True),
+        ('a(a, b, (a for a in b), c, d)', True),
+    ]
+)
+def test_unparenthesized_genexp(source, no_errors):
+    assert bool(_get_error_list(source)) ^ no_errors
+
+@pytest.mark.parametrize(
+    ('source', 'no_errors'), [
+        ('*x = 2', False),
+        ('(*y) = 1', False),
+        ('((*z)) = 1', False),
+        ('a, *b = 1', True),
+        ('a, *b, c = 1', True),
+        ('a, (*b), c = 1', True),
+        ('a, ((*b)), c = 1', True),
+        ('a, (*b, c), d = 1', True),
+        ('[*(1,2,3)]', True),
+        ('{*(1,2,3)}', True),
+        ('[*(1,2,3),]', True),
+        ('[*(1,2,3), *(4,5,6)]', True),
+        ('[0, *(1,2,3)]', True),
+        ('{*(1,2,3),}', True),
+        ('{*(1,2,3), *(4,5,6)}', True),
+        ('{0, *(4,5,6)}', True)
+    ]
+)
+def test_starred_expr(source, no_errors):
+    assert bool(_get_error_list(source, version="3")) ^ no_errors

test/test_utils.py

@@ -1,6 +1,11 @@
 from codecs import BOM_UTF8
 
-from parso.utils import split_lines, python_bytes_to_unicode
+from parso.utils import (
+    split_lines,
+    parse_version_string,
+    python_bytes_to_unicode,
+)
+
 import parso
 
 import pytest
@@ -63,3 +68,35 @@ def test_utf8_bom():
     expr_stmt = module.children[0]
     assert expr_stmt.type == 'expr_stmt'
     assert unicode_bom == expr_stmt.get_first_leaf().prefix
+
+
+@pytest.mark.parametrize(
+    ('code', 'errors'), [
+        (b'# coding: wtf-12\nfoo', 'strict'),
+        (b'# coding: wtf-12\nfoo', 'replace'),
+    ]
+)
+def test_bytes_to_unicode_failing_encoding(code, errors):
+    if errors == 'strict':
+        with pytest.raises(LookupError):
+            python_bytes_to_unicode(code, errors=errors)
+    else:
+        python_bytes_to_unicode(code, errors=errors)
+
+@pytest.mark.parametrize(
+    ('version_str', 'version'), [
+        ('3', (3,)),
+        ('3.6', (3, 6)),
+        ('3.6.10', (3, 6)),
+        ('3.10', (3, 10)),
+        ('3.10a9', (3, 10)),
+        ('3.10b9', (3, 10)),
+        ('3.10rc9', (3, 10)),
+    ]
+)
+def test_parse_version_string(version_str, version):
+    parsed_version = parse_version_string(version_str)
+    if len(version) == 1:
+        assert parsed_version[0] == version[0]
+    else:
+        assert parsed_version == version